Objective We describe cases of invasive group A Streptococcus (iGAS) in mothers or neonates and assess management according to national guidelines, which recommend administering antibiotics to both mother and neonate if either develops iGAS infection within 28 days of birth and investigation of clusters in maternity units.Design Cross-sectional retrospective study. Setting and population Notified confirmed iGAS cases in either mothers or neonates with onset within 28 days of birth in London and the South East of England between 2010 and 2016Method Review of public health records of notified cases.Main outcome measures Incidence and onset time of iGAS in postpartum mothers and babies, proportion given prophylaxis, maternity unit clusters within 6 months.Results We identified 134 maternal and 21 neonatal confirmed iGAS infections. The incidence (in 100 000 person years) of iGAS in women within 28 days postpartum was 109 (95% CI 90-127) compared with 1.3 in other females aged 15-44. For neonates the incidence was 1.5 (95% CI 9-23). The median onset time was 2 days postpartum [interquartile range (IQR) 0-5 days] for mothers and 12 days (IQR 7-15 days) for neonates. All eligible mothers and most (109, 89%) eligible neonates received chemoprophylaxis. Of 20 clusters (59 cases of GAS and iGAS) in maternity units, two clusters involved possible transmission. However, in 6 of 15 clusters, GAS isolates were not saved for comparison even after relevant guidance was issued.Conclusions iGAS infection remains a potential postpartum risk. Prophylaxis among neonates and storage of isolates from maternity cases can be improved.

In the United Kingdom, pertussis guidance recommends prophylaxis for household contacts within 21 days of case symptom onset if the household includes a vulnerable contact. The aim of our study was to identify characteristics associated with cases reported late for public health action. We reviewed the epidemiology of cases reported in London and South East England for the period 2010 to 2015. We characterised risk factors associated with late reporting of cases and described public health actions taken on timely reported cases. From 2010 to 2015, 9,163 cases of pertussis were reported to health protection teams. Only 11% of cases were reported within 21 days of onset, limiting opportunities for secondary prevention. Timely reporting was associated with younger age groups, pregnancy, being a healthcare worker and being reported by schools or hospital clinicians. Late reporting was associated with older age groups and general practitioner or laboratory reporting. Delays, such as those due to insidious onset and late presentation to healthcare, may be unavoidable; however, delay in reporting once a patient presents can be reduced since cases can be reported before laboratory confirmation. Thus we recommend working with clinicians and laboratories to determine causes and improve early reporting to public health.